Question

As titled.

But still, users can login to the frontend, and administrator could create user account only in backend.

Answer 1

Ok. I got it worked. Refer to Hugues Solution, there are two amendments:

1. add app\etc\modules\Mycompany_All.xml

   <?xml version="1.0"?>
   <config>
       <modules>
           <Mycompany_Registrationremove>
               <active>true</active>
               <codePool>local</codePool>
           </Mycompany_Registrationremove>
       </modules>
   </config>
   

2. modify the file: app/code/local/Mycompany/Registrationremove/etc/config.xml

   <?xml version="1.0"?>
   <config>
       <modules>
           <Mycompany_Registrationremove>
               <version>0.1.0</version>
           </Mycompany_Registrationremove>
       </modules>
    <global>
           <rewrite>
               <mycompany_registrationremove_customer_account_create>
                   <from><![CDATA[#^/customer/account/create/$#]]></from>
                   <to>/registrationremove/customer_account/create</to>
               </mycompany_registrationremove_customer_account_create>
               <mycompany_registrationremove_customer_account_createPost>
                   <from><![CDATA[#^/customer/account/createPost/$#]]></from>
                   <to>/registrationremove/customer_account/createPost</to>
               </mycompany_registrationremove_customer_account_createPost>
           </rewrite>
       </global>
       <frontend>
           <routers>
               <mycompany_registrationremove>
                   <use>standard</use>
                   <args>
                       <module>Mycompany_Registrationremove</module>
                       <frontName>registrationremove</frontName>
                   </args>
               </mycompany_registrationremove>
           </routers>
       </frontend>
   </config>